Function findModule

packages/schematics/angular/utility/find-module.ts:84–125

(
  host: Tree,
  generateDir: string,
  moduleExt?: string,
  routingModuleExt?: string,
)

 * Function to find the "closest" module to a generated file's path.
 */
export function findModule(
  host: Tree,
  generateDir: string,
  moduleExt?: string,
  routingModuleExt?: string,
): Path {
  let dir: DirEntry | null = host.getDir('/' + generateDir);
  let foundRoutingModule = false;

  const moduleExtensions: string[] = moduleExt ? [moduleExt] : [MODULE_EXT, MODULE_EXT_LEGACY];
  const routingModuleExtensions: string[] = routingModuleExt
    ? [routingModuleExt]
    : [ROUTING_MODULE_EXT, ROUTING_MODULE_EXT_LEGACY];

  while (dir) {
    const allMatches = dir.subfiles.filter((p) => moduleExtensions.some((m) => p.endsWith(m)));
    const filteredMatches = allMatches.filter(
      (p) => !routingModuleExtensions.some((m) => p.endsWith(m)),
    );

    foundRoutingModule = foundRoutingModule || allMatches.length !== filteredMatches.length;

    if (filteredMatches.length == 1) {
      return join(dir.path, filteredMatches[0]);
    } else if (filteredMatches.length > 1) {
      throw new Error(
        `More than one module matches. Use the '--skip-import' option to skip importing ` +
          'the component into the closest module or use the module option to specify a module.',
      );
    }

    dir = dir.parent;
  }

  const errorMsg = foundRoutingModule
    ? 'Could not find a non Routing NgModule.' +
      `\nModules with suffix '${routingModuleExt}' are strictly reserved for routing.` +
      `\nUse the '--skip-import' option to skip importing in NgModule.`
    : `Could not find an NgModule. Use the '--skip-import' option to skip importing in NgModule.`;

  throw new Error(errorMsg);
}

/**
 * Build a relative path from one file path to another file path.